A member here has a set of ZSP (springs and shocks) for sale from his E92 335i.. I was wondering, would the ZSP fit my E90 323i? I know the springs will be more stiff, but i don't mind it that much. I just want it to be perfect fit so i can get a small drop on my 323i.

If your going for the upgrade of your suspension, why not go aftermarket with coilovers or lowering springs...The oem sports suspension is not that great even...Higher rmps the car feels and tends to be light on its feet.